1. Field of the Invention
The present invention relates to a thyristor having a controllable emitter short circuit in which the thyristor has a semiconductor body which contains an outer n-emitter layer carrying a cathode, an outer p-emitter layer carrying an anode and two base layers respectively adjacent thereto, and comprising a controllable emitter short circuit.
2. Description of the Prior Art
A thyristor of the type generally set forth above is known from U.S. Pat. No. 3,243,669. In that patent, the controllable emitter short circuit comprises a metal-insulator-semiconductor (MIS) structure which has a gate separated from the semiconductor body by a thin, electrically insulating layer. Upon the application of a control voltage to the gate, a short circuit path is turned on which bridges the pn junction between the emitter layer connected to the anode and the adjacent base layer. This results in the switching of the thyristor from the current-conducting condition into the blocked condition in which practically no current flows between the anode and cathode despite a voltage applied in the forward-conducting direction. What is disadvantageous is that the MIS structure is sensitive to very high gate voltages which, for example, can arise due to an undesired charging of the gate.